1,3-Dioxolane → Acyclovir

Participants

Reaction Conditions

Reaction Steps

A mixture of guanine (25 g) , hexamethyldisilazane (HMDS, 125 ml), and trimethylsilyl trifluoromethanesulfonate (1 ml) was heated to reflux (130°-135° C.) for 24 hours. The resulting mixture was cooled to 70° C., 1,3-dioxolane (25 ml) added, and the resulting mixture refluxed for 16 hours. Excess HMDS and 1,3-dioxolane were removed by distillation under reduced pressure. The reaction mixture was cooled to 70° C., and poured into a mixture of 600 ml of 10% aqueous acetic acid. The mixture was heated to give a solution. The hot solution was treated with a small amount of activated carbon (1.25 g) to remove any color, filtered, and the filtrate slowly cooled to 5° C. The white crystalline solid thus produced was filtered off, to yield pure 9-(2-hydroxyethoxymethyl)guanine (29 g, 78%). 1H NMR: 3.38 (4H, singlet); 4.64 (1H, broad singlet); 5.26 (2H, singlet); 6.54 (2H, broad singlet); 7.68 (1H, singlet).

Provenance & Evidence